Untitled

Energy ↑
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   σ* (mostly H 1s character, antibonding)        (empty)
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   nonbonding  (F 2p_x)        2 e⁻
   nonbonding  (F 2p_y)        2 e⁻
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   σ (bonding: H 1s + F 2p_z)  2 e⁻
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   F 2s (largely nonbonding / low σ mixing)     2 e⁻
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(core: F 1s)   (not shown)